Welsh interference is possible, specially given the meaning, but I don’t think that it explains alone what’s going on. The Welsh word is araf; there’s also the associated verb arafu “to slow down”, but none of those forms show ⟨ff⟩, or ends with ⟨e⟩.
Maybe slow like in Welsh.
Welsh interference is possible, specially given the meaning, but I don’t think that it explains alone what’s going on. The Welsh word is araf; there’s also the associated verb arafu “to slow down”, but none of those forms show ⟨ff⟩, or ends with ⟨e⟩.